Microphone and loud-speaker system for churches, public halls and the like



Dec. 13, 1932. R. .MEssMER 1,890,742

MICROPHONE AND LoUD SPEAKER SYSTEM EUR CHURCHES, PUBLIC HALLs, AND THE LIKE Filed June 27, 1932 Patented Dec. 13, i932 PATENT OFFICE BODOLPHE MESSMER, OF MONTREAL, QUEBEC, CANADA lucnornoim .um Loon-SPEAKER .Application` led June 27,

The present invention relates to a sound amplifying system, and-pertains more particularly to a'type adapted `to be used" in churches, public halls and the like.

Nowadays, it is common to use loud-speakers, in halls and churches forr the purpose of amplifying thevoice of the speaker, for example, to render the same intelligible to all present.

'Inasmuch as a microphone is disposed directly in front of the speaker, ,to pick up the sounds, itis imperative thatv the loud-speakers be ydisposed at a certain distance from said Y microphone, toavoid .feed-hacker howling.\ 5 Furthermore, the output from said microphone being limited, as alfurtheraid against howling, it `is necessary for the speaker to face the said microphone at all times and to remain with a restricted field therefrom.

` This restricte'dfield for the speaker is'in itself a serious drawback since av temperamental oratory generally moves about and esticulates more or less according to his sub- ]ect. l Consequently, a speech delivered under t '25 these conditions is generally'flat and lifeless,

due tothe fact that vthe speaker has to limit his movements, and refrain from moving his head a reat deal. `1 y l Possi ly the greatest drawback of this system, from the speakers standpoint, is due to the echo of his own voice which occurs generall a fraction of lay second after he has uttere n the corresponding sounds; this lag. 1s l the more4 accrued as the loud-speakers are 1nstalled farther from the speaker himself.

yThe present invention, on the `other hand, remedies the above defects o f an amplifying system, and provides unlimited possibilities for the most enthusiastic s eaker who can move freel about his plat orm without in the leasta ecting the output of the soundre roducers. ,l .Y

herefore, the'primary object of the inven- V tion is a sound reproducing system for balls and the like, wherein fthe speaker is not hamered by anyvisible apparatus, and which 1s furthermore free from sound-lag, as taken 'Y from the speakers view oint. y Asan example, and orl purposes of illustration, a `pr ferred example of the invention y or even a wall.

sYsfrnMy ron CHURCHES, PUBLIC HALLs A,AND THE LIKE 1932. Serial No. 619,478.

`is shown in the attached drawing wherein similar reference numerals designate corresponding parts throughout the same. f

In the drawing, Fig. 1 is an elevation of a pulpit according 55 to the invention, and showing the relation between the speaker and the pulpit canopy. Fig. 2 is a plan view of the under faceof the canopy, n Fig. 3 is a longitudinal section through said 60 canopy, and illustrating the arrangement of microphones and loud-speakers,

Fig. 4L is an enlarged View oi' themicrophone-loudspeaker arrangement, and t Fig. 5 is a View taken online 55 of Fig. 2. 65- Referring to the drawing, the numeral 10 generally indicates a pulpit or the like havmg a canopy 11 supported by a standard 12,

The canopy-may preferably be set at an angle from the horizontal for Various reasons, and principally to meet acoustic laws of sound diusion; i

The under face of the canopy has secured 'y thereto a great number of diaphragms or plates 13, embossed to affect a leaf-likeshape, and somewhat conical when viewed longitudinally. These diaphragms form thesubj ect matter of my U. S. Patent No. 1,795,178 issued March 3rd, 1931, and a more detailed expla- 80 nation of their use may be found therein.

Apart from the excellent diiusion properties of these daphragms or plates when used in ordinary pulpits, these plates are y, adapted for the purpose of the invention for a reason to be described later.

'The method ofv assembling and securing these plates 13 to the canopy 11 is shown in Fig. 5, as an example, orsoldering maybe resorted to. As an aid for properly asten- 9U ing the edges of the plates in place, and for canopy-bracing purposes, a series of transverse bars 14 are provided t0 which the plates are nailed. (Figs. l and 5.) t

After the canopy is completelyV covered with the plates, the sectional line defined by the outer surface of said plates is substantially as shown in Fig. 3. Each plate comprises a long side and a shorter side angularly disposed with respect to the former.

` ral sound-diffusion qualities, has been moti- As shown to advantage in Fig. 4, a microphone 15 is disposed in an aperture provided in the'short side of each plate 13, and serves to pick the sounds or speech uttered by the speaker below. This microphone is best supported by springs 16 and further enclosed, on the inner side of the plate, inside a soundproof box 17 of softmaterial, or preferably of wood-fibre, cane sugar fibre or other pressed board. y Y,

The output from the microphones 15 is suitably amplified by means of an amplifier 18, wherein the output of all microphones is suitably mixed, and thereafter fed to a plurality of loud-speakers 19 disposed lon the outside peripheral margin of the. canopy.

Thus,V the sound impulses picked up by the microphones areV amplified and reproduced faithfully by the reproducers.

Due to the great number of the microphones, the movements of the orator below are not noticeable in the delivered output which remains constant, no matterin whichy direction the speaker may move, since theV mean total from the battery of microphones is always constant as long as the speaker Vmoves within the field thereof.`

trouble is experienced in this direction; theV speaker is quite free from any visible appa.- ratus and may give the full measure of his talent quite naturally.

Furthermore, due to the closeness of the loud-speakers to theV orator, the time lag is so small as to be entirely unnoticeable by the speaker himself. Y. V Y

As already pointed out, the choice of the leaf-shaped plates 13, aside from their natuvated by another consideration. Considering Fig. 4, it will be seen that the greatest percentage of the sound issuing from the reproducer 19 is directed according to the arrows 20, directly into space. However, re-

flections and echoes being always present in any building, disturbing sound impulses reflected back to the sound source may be eX- Y pected. These reflections are encountered in practice and are mainly the cause of howling or feed-back, since engineers generally take great pains tof insure that microphones are not disposed in the path of the direct output from loud-speakers.

The problem of these reflections is successfully met inthe present ease, due to the particularv arrangement of the microphones with respect to the loud-speakers. This is shown in ig. 4, wherein arrows 21', indicative of reflections from the walls of the building, are deflected by the plates l'away from the microphone 15. Said microphone is thus left undisturbed by the reiiected sound, and is f the subjoined claims.

acted upon by the sound from the speaker only, as shown by the arrows 22.

Other constructive-features of the system include the spring suspension of the microphones to dampen vibrations existing in the canopy structure, and the sound-proof box 17 around the microphones shutting off the sound waves issuing from the inside surface of the loud-speaker diaphragm, when a cone speaker is used. Incidentally, although a loud-speaker of the cone type has been illustrated, it is evident that a horn orexponentialreproducer can be used as well7 the more vso when directional properties are required in the system. f

From theforegoing, it will be apparent that the lpresentfarrangement constitutes a most satisfactory solutionrto the problem of public address systems, when used in halls, churches or the like wherein the acoustic properties of thepbuilding are not all that can be desired. ,c

Itis to be understood that various changes asto arrangement and substitution of parts can be resorted to without departing from the spiritV of the invention and the scope of Having thus described my invention, I lclaim:-- V c l l. A sound reproducing system, comprising sound operated microphones, means to amplify the electrical impulses from the microphones, sound reproducing devices operated by theamplifyingmeans, and means between the sound reproducers and microphones to rdeflect the sound waves issued from the sound reproducers away from the field of the microphones. Y

' 2. In a sound reproducing system, microphonesv disposed in one plane, means for the microphones, Vsound lreproducersfed from the amplifying means and disposed slightly above the plane ofthe microphones, and angular means between `the reproducers and microphonesVA to deflect the sound waves issued from the reproducers away from the microphones. y,

'3. The invention as deiined in claim 2, wherein the deflecting means between microphones and reproducers comprise a plurality of plates of corrugated surface and of angular formation. l

4. A sound reproducingY system, comprising a plurality of microphones disposed in a plane above a speaker,v sound reproducers slightly above the plane of said microphones and around the peripheral margin defining said plane, means to feed ysaid reproducers from impulses picked up bythe microphones, and a pluralit of platesin the same plane ofthe -microp ones, whereby ,soundt issued from the reproducers is defiected'away'from the microphones. f

5. A soundreproducingsystem comprising in combinationwwiththe eanopyof a pulpit,

amplifying a plurality of sound-diffusing plates covering Ythe under side of the canopy,`microphones suitably disposed in apertures provided in said plates, audio amplifier means to step up the electrical impulses produced by the microphones, and loud s eakers disposed on the peripheral margin o? the canopy and fed from the audio amplifier.

6. In a sound reproducing system as claimed in claim 5, sound-diffusing plates comprising a diaphragm-like plate having a leaf-like embossing thereon, of angular crosssection whereby a long anda short side is provided and means in the short side to receive a microphone, the long side y being directed away from the microphone to effectively delect downwardly sound waves reflected from Vbodies surrounding the canopy.

'In witness whereof I have hereunto set my hand. f

RODOLPHE MESSMER. 

